Nissan Rogue Service Manual: System

System Diagram

1. Compressor
2. Pressure relief valve
3. Liquid tank
4. Refrigerant pressure sensor
5. Condenser
6. Expansion valve
7. Evaporator
8. Blower motor

1.  High-pressure gas
2.  High-pressure liquid
3. Low-pressure liquid
4. Low-pressure gas
5. Suction port
6. Discharge port
7.  Outside air

System Description

REFRIGERANT CYCLE

Refrigerant Flow

The refrigerant from the compressor flows through the condenser and liquid tank, evaporator, and returns to the compressor. The refrigerant evaporation in the evaporator is controlled by an expansion valve.

Freeze Protection

To prevent evaporator from freezing up, the evaporator air temperature is monitored and the voltage signal to the A/C auto amp. makes the A/C relay go OFF and stop the compressor.

REFRIGERANT SYSTEM PROTECTION

Refrigerant Pressure Sensor

•  The refrigerant system is protected against excessively high or low pressures by the refrigerant pressure sensor, located on the liquid tank. The refrigerant pressure sensor detects the pressure inside the refrigerant line and sends the voltage signal to the ECM if the system pressure rises above or falls below the specifications.
•  ECM turns the A/C relay to OFF and stops the compressor when the high-pressure side detected by refrigerant pressure sensor to have the following conditions:
•  Approximately 3,120 kPa (31.8 kg/cm2, 452 psi) or more (Engine speed is 1,500 rpm or more.)
•  Approximately 2,740 kPa (27.9 kg/cm2, 397 psi) or more (Engine speed is less than 1,500 rpm.)
• Approximately 120 kPa (1.2 kg/cm2, 17 psi) or less

Pressure Relief Valve

The refrigerant system is also protected by a pressure relief valve, located in the rear head of the compressor.

The release port on the pressure relief valve automatically opens and releases refrigerant into the atmosphere when the pressure of refrigerant in the system increases to an unusual level [more than 3,800 kPa (38.8 kg/ cm2, 551 psi)].